Mouthpiece for an underwater breathing device



Nov. 9, 1965 w. F. MITCHELL 3,216,416

MOUTHPIECE FOR AN UNDERWATER BREATHING DEVICE Original Filed Sept. 15, 1955 3 Sheets-Sheet 1 I3l I33 I32 I28 I30 I 8 ,3 I42 I36 |6| I41 I43 I22 I27. j I49 I20 I n9 5o 4 es 8 59 no I65 IoI- 72 l I 250 74 H2 \JOZW' I 5 73 5l 6% I 63 75 I60 50 I62 k 8 7o 4o 42 3o 4 22 36 1- 24 38 :47: l 48 I I5 I I \J INVENTOR. I

WALLACE F. MITCHELL BY ATTORNEYS Nov. 9; 1965 W. F. MITCHELL MOUTHPIECE FOR AN UNDERWATER BREATHING DEVICE Original Filed Sept. 15, 1955 F l G. 4

3 Sheets-Sheet 2 lo I4s I05 I M030 I82 I84 I83 I74 I8! I87 es- I85 I78 I I3 I40 H a 80 I75 24 5 I73 I76 I83 -l86 74 I84 85 I78 J, I87

I80 I77 20 I4 INVENTOR.

I79 WALLACE F. MITCHELL ATTORNEYS Nov. 9, 1965 w. F. MITCHELL 3,216,416

MOUTHPIECE FOR AN UNDERWATER BREATHING DEVICE Original Filed Sept. 15, 1955 5 h tshe t 3 FIG. 6

INVENTOR.

WALLACE F. MITCHELL ATTORNEYS United States Patent Ofiice 3 ,2 l 6 ,4 l 6 Patented Nov. 9, 1965 3,216,416 MOUTI-IPIECE FGR AN UNDERWATER BREATlHNG DEVICE Wallace F. Mitchell, Arlington Heights, 111., assignor to Dacor Corporation, Evanston, 111., a corporation of Illinois Original application Sept. 15, 1955, Ser. No. 535,067, now Patent No. 3,028,859, dated Apr. 10, 1962. Divided and this application Sept. 12, 1963, Ser. No. 309,591 2 Claims. (Cl. 128147) This application is a continuation in part application of my copending application, Serial No. 68,193, filed November 9, 1960 and now abandoned, which is a divisional application of my earlier application, Serial No. 535,067, filed September 15, 1955 and now Patent No. 3,028,859.

This invention relates to underwater breathing devices and has to do more particularly with an underwater breathing device of the self-contained type.

Self-contained underwater breathing devices as heretofore constructed have usually included a tank of compressed air, an air intake hose line leading from the tank to a mouthpiece adapted to be held in the mouth of the user and an exhaust air hose line leading from the mouthpiece to a one-way discharge or exhaust valve. Connected to the intake line is a pressure regulator adapted to reduce the pressure of the compressed air to that of the surrounding water and to avoid the loss of air. In such devices the pressure regulator includes a regulator chamber defined in part by a flexible diaphragm which is exposed at one face of the water and consequently is subjected to the pressure of the water, the diaphragm being arranged to cause the opening of a demand valve in the regulator leading to the intake hoseline whenever the pressure in the intake line is a predetermined amount less than the water pressure, such as when the user inhales.

Heretofore, difliculty has been encountered in the design and construction of a leakproof assembly of the hoses and mouthpiece, particularly where flexible hoses and elastomeric mouthpieces have been employed. The flexible hoses and elastomeric mouthpiece present a leakage problem at the parting line thereof and clamp means heretofore employed to secure the hoses to the mouthpiece have not completely eliminated this leakage problem, because of the capacity of the material of construction of the hoses or of the mouthpiece to deform.

The aforementioned problems and difficulties of the prior art, among others, are substantially overcome with the present invention by the employment of a new and improved arrangement of hoses and mouthpiece wherein the hose ends have the mouthpiece disposed therein, the intake and outlet valves in the mouthpiece are located concentrically with the hoses, and clamps secure the hoses to the mouthpiece and also retain the valves in the mouthiece. p Construction of the valves so that they have a rigid body portion facilitates securing of the hoses to the mouthpiece and retention of the valves in the mouthpiece to provide a leakproof assembly of hoses, mouthpiece and valves.

Accordingly, an object of my invention is to provide a new and improved, self-contained, underwater breathing device.

Another object of the present invention is to provide new and improved underwater breathing apparatu having a leakproof assembly of intake and outlet hoses and mouthpiece.

Still another object of the present invention is to provide new and improved underwater breathing apparatus having removable intake and output valves retained in the mouthpiece by the same means securing the intake and outlet hoses to the mouthpiece.

A further object of the present invention is to provide underwater breathing apparatus including a concen tric arrangement of removable intake and output valves, each having a rigid body portion, elastomeric or deformable intake and output hose ends, elastomeric mouthpiece and clamp means for securing the hoses to the mouthpiece and retaining the valves in the mouthpiece.

A still further object is to provide new and improved under water breathing apparatus including a mouthpiece constructed of elastomeric material and having shoulders for locating removable intake and output valves and intake and output hose ends concentrically so that concen tric clamp means may be employed which secure the hose to the mouthpiece and retain the valves in the mouthpiece.

Another object of the present invention is to provide new and improved underwater breathing apparatus including a mouthpiece having internal and external shoulders formed integral therewith for facilitating assembly thereof with intake and output valves and intake and out put hoses to provide a leakproof arrangement.

Still another object of the present invention is to provide underwater breathing apparatus including a mouthpiece which is simple and compact in construction.

These and other objects, features and advantages of the present invention will become readily apparent from a careful consideration of the following detailed description when considered in conjunction with the accompanying drawings, illustrating preferred embodiments of the present invention, wherein like reference numerals and characters refer to like and corresponding parts through out the several views, and wherein:

FIGURE 1 is a fragmentary front elevational view of the device showing particularly the pressure regulator and portions of the air lines and air tank;

FIGURE 2 is an enlarged fragmentary sectional view taken along line 22 of FIGURE 1;

FIGURE 3 is a somewhat diagrammatic showing of the device with parts broken away and in section to show the interior construction, the device being shown in the condition it assumes during the inhale cycle;

FIGURE 4 is a view similar to FIGURE 3 only showing the device in the condition it assumes during the exhale cycle;

FIGURE 5 is a view of a section taken along line 55 of FIGURE 4;

FIGURE 6 is a view of a section taken along line 6-6 of FIGURE 2;

FIGURE 7 is a view of a section taken along line 77 of FIGURE 2;

FIG. 8 is a view of a section taken along line 88 of FIG. 2; and

FIG. 9 is a view of a section taken along line 9-9 of FIG. 2.

The device in accordance with my invention includes a tank or flask 10 for containing compressed air, a regula tor 11 connected to the flask 10 by a clamp 12 for regulating the withdrawal of air from the flask 10, an air hose 13 connected to the regulator, and a mouthpiece 14 connected to the air hose 13 for inhaling air from the flask through one part of the air hose and for exhal'ing air from the lungs through another part of the air hose. The clamp 12, the regulator 11, the air hose 13 and the mouthpiece together constitute an assembly which may be detached from the flask 10 as a unit in order to permit replacement of the flask, which assembly I designate as a breathing unit.

The flask 10 may be of any suitable'conventional construction and is of sufficient. strength to contain air at the customary pressure of approximately 2,000 pounds per square inch. It is provided with the usual neck 15 having an outlet passage 16 therein leading from the I ject to deterioration.

interior of the tank. The clamp 12 is suitably formed to clamp the regulator 11 to the neck 15, a clamp screw (not shown), having a suitable handle, being provided for tightening the clamp to draw the regulator into sealing engagement with the neck and to hold the regulator on the neck until the clamp is released. The tank is provided with the usual manually operated shut-off valve (not shown) for closing the tank to prevent loss of air when the device is not in use and especially where the tank is disconnected from the regulator.

The regulator 11 includes a body 20 having a recess therein providing a primary reduction chamber 21. A primary valve housing 22 is threaded into a bore 23 in the body 20 leading to the primary reduction chamber 21. The primary valve housing 22 has a passage extending therethrough which provides communication between the outlet passage 16 of the tank and the primary reduction chamber 21. The primary valve housing 22 is formed with a flange 24 for the purpose of engaging the clamp 12 and retaining the pressure regulator on the neck 15, which flange is preferably of hexagonal shape in order to racilitate screwing the primary valve housing into the body 20.

The passage in the primary valve housing 22 is formed with a circular bore portion 36) and orifice 31 and a second circular bore portion 32, all of which are in alignment. Thus the bore portions 30 and 32 and the orifice 31 provides. continuous passage for air from the outlet passage 16 to the primary reduction chamber 21.

Formed around the orifice 31 is a valve seat 35 of annular form and having a reduced outer face or edge portion providing an annular valve seat of relatively narrow Width.

A primary valve 36 is slidably disposed in the bore 30 for movement between closed position abutting the valve seat 35 and an open position spaced from the valve seat. The primary valve 36 includes a body 37 of generally square cross-sectional shape as seen particularly in FIG.

9 of the drawings and therefore a plurality of passages 38 are provided between the valve body 37 and the bore 30 to permit air to pass around the valve member.

The valve member 37 is provided with a recess 40 in which is disposed a valve insert formed of flexible resilient sealing material. The material from which the insert 41 is formed is one which retains its resiliency and sealing properties over long periods of use and is not sub- Preferably, I form the insert from a suitable plastic, and for this purpose I have found that a polytetrafluoroethylene plastic marketed by E. I. du Pont de Nemours and Co., of Wilmington, Delaware, under the trade name Teflon has provided excellent results.

The recess 40 is disposed axially of the primary valve member 37 and the insert 41 is symmetrically disposed in the recess. Disposed axially within the recess and within the insert 40 is an anvil element 42 formed of metal which is secured in the material of the valve member 37 below the bottom of the recess 40 so as to be held firmly and securely therein. The corresponding faces of the valve member 37, the insert 41 and the anvil 42 are very carefully machined so that they all lie in the same plane and particularly the end faces of the insert 41 and the anvil 42. Preferably, I form the assembly constituting the valve 36 by disposing the insert and anvil in the recess 41 and staking the end face of the valve member 37 to crimp the edge around the insert, whereafter the end faces of all three members are machined off so that they are flush.

The valve 36 is urged into closed position against the valve seat 35 by a spring 45 seated in a recess 46 in the valve member 37 and bearing at its outer end against a retainer 47 rigidly secured in the valve housing 22 over the end of the bore 30. The seat member 47 is formed with an opening therein to permit the passage of air therethrough, and a screen 48 is secured across the bore 30 by the member 47 for preventing the passage of any solid particles into the bore 30.

The outer side of the primary reduction chamber 21 is closed by a diaphragm 50 extending across the face of the body 20 and clamped thereto by an intake housing 51 secured in place by a plurality of screws 52 extending through the end wall of the housing 51 and threaded into the body 20. The diaphragm 50 is formed from a suitable, flexible, resilient, waterproof material, such as rubber. Carried centrally of the diaphragm 50 is a pusher member 55 having a stem 56 extending through an opening 57 in the diaphragm 50 and secured to the diaphragm by a nut 58. The nut 58 bears against a bearing washer 5911 which serves to clamp the central portion of the diaphragm 50 between itself and the head of the push member 55. The push member has a head 59 on the inner side of the diaphragm adapted to bear against the head 61 of a push rod 61 having a stem 62 positioned to engage the exposed end of the anvil 42 for moving the primary valve 36 away from its seat.

The head 69 of the push rod 61 is formed of generally square cross-section and whereby there is provided passages 63 around the head 60 from the inner portion of the bore 32 to the primary reduction chamber 21.

The push member 55 is normally urged inwardly to cause the push rod 61 to move the valve 36 off its seat by a spring 65 bearing at one end against the push member 55 and at the other end against a spring retainer 66 having a flange portion 67a bearing against the inner face of the intake housing and secured to the body 20 by the screws 52 and a cup portion 67 for retaining and seating the spring 65.

The primary valve serves to permit the flow of air from the flask 10 to maintain a predetermined air pressure within the primary reduction chamber 21. Preferably, the pressure of the air maintained within the primary reduction chamber 21 is about 50 to 100 pounds per square inch. Whenever the pressure of the air within the primary reduction chamber 21 falls below the desired value, the spring 65 urges the pressure member 55 'inwardly, which in turn urges the push rod inwardly and thereby moves the primary valve 36 away from its seat to let air pass through the outlet passage 16, the screen 48, the passages 38, the valve orifice 31, the bore 32 and the passages 63 and into the primary reduction chamber 21. When the desired presssure within the chamber 21 is reestablished, the diaphragm 50 is moved outwardly against the force of the spring 65 to thereby permit the spring 45 to seat the valve 36 and cut off further flow of air from the tank to the primary reduction chamber.

Leading from the primary reduction chamber 21 is a passage 70 which communicates with a bore 71 in which is threaded a demand valve seat member 72 which extends through suitably positioned openings in the diaphragm 50, the bottom wall of the intake housing 51, and the spring retainer 66 and the foot of a bracket 73 hereinafter described more in detail. The valve seat member 72 takes the place of one of the screws 52 and secures the bracket 73 in place. The valve seat member 72 is formed with a flange 74 seated against the bracket 73, and has a tapered seat portion at its outer end providing an annular seat of relatively small width. A bore 75 extends through the valve seat member 72 and provides communication between the bore 71 and the interior of the intake housing 51.

The valve bore 75 is normally closed by a demand valve formed of resilient sealing material such as rubber or a synthetic material such as- Teflon. The valve 80 is carried by a lever 81 pivotally supported as at 82 from the bracket 73. Thus the valve 80 is adapted to be moved into and out of position in closing the valve port or passage 75. The valve 80 is normally urged into closed position by a spring which is seated at one end against the nut 58 and at the other end against the demand valve lever 81, the latter being formed with a boss or button 91 struck up from the material of the lever and which enters the corresponding end of the spring to retain the spring in its appropriate position relatively to the lever 81.

A second valve-operating lever 100 is pivoted as at 101 to a bracket 102 secured by one of the screws 52, which lever 100 is adapted to operate the demand valve lever 81 to open the demand valve. The lever 100 has a boss or button 103 formed with its outer end adapted to be actuated by a breather diaphragm 105 hereinafter described. The valve actuating lever 100 is so arranged that it engages intermediate its ends and preferably about half Way between its ends a boss or button 106 formed on the outer end of the lever 81.

It will be seen from the foregoing that when the lever 100 is depressed it bears against the button 106 and effects a depression of the lever 81, which raises the demand valve 80 off its seat to permit air to flow from the primary reduction chamber 21 to the passage 70, the bore 71 and the port 75 and into the interior of the intake housing 51.

The intake housing 51 and the valve operating or breather diaphragm 105 together define an intake chamber 110 which is connected to the interior of the flask through the passages hereinbefore described. The relative sizes of the passages connecting the interior of the flask with the interior of the inlet chamber 110, and particularly the passages leading from the pressure reduction chamber 21 to the intake chamber 110, are such that the air is maintained in the intake chamber 110 at substantially the pressure of the medium surrounding the pressure regulator.

The intake housing is of generally cupped form and has a bottom Wall 111 of circular form and a side wall 112 upstanding therefrom. Extending outwardly from the outer end of the side wall 112 is a flange 113 having an upturned rim 114. The breather diaphragm 105 is formed from a suitable flexible resilient material which is watertight and which is not subject to deterioration over a long period of use, or loss of flexibility and re silence, and preferably I form such diaphragm from rubber, reinforced with a nylon core. The breather diaphragm 105 has a central portion 115 which is rigid and non-flexible and which has secured thereto on both faces thereof circular reinforcing plates 116 of thin metal secured to the diaphragm in a suitable manner as by rivets 117. Outwardly of the reinforced portion is a flexible resilient portion 118 of annular form and outwardly thereof is a securing rim portion 119 of greater thickness which is sealingly secured to the flange 113 of the intake housing 51 by screws 120 which extend through the flange 113 and are secured by nuts 121.

Disposed outwardly of and in clamping engagement with the rim portion 119 is a circular exhaust ring 125 of generally channel shape in cross-section and having a main wall or web 126 and flanges 127 and 128 extending inwardly therefrom providing a generally U shaped cross-section.

Secured against the outer face of the flange 128 of the exhaust ring is an exhaust diaphragm 130 which is generally similar in form and structure to the breather diaphragm 105 except as hereinafter explained. Outwardly of the exhaust diaphragm 130 is a cover 131 of generally disc-shaped form and having a wall portion 132, an inclined wall portion 133 extending therefrom in which is provided a plurality of openings 134. Outwardly beyond the wall portion 133 is a flange 135 having a downturned rim 135a. The securing screws 120 extend through the flange portions 135 and secure the cover 131 in place on the exhaust ring 125 and at the same time clamp the rim portion 136 of the diaphragm 130 between the flange 135 and the flange 128. The diaphragms 130 and 105 define therebetween an exhaust chamber 140 which communicates with the exterior of the pressure regulator through an exhaust valve now to be described.

The diaphragm has a central portion 141 which is reinforced by reinforcing members 142 secured by rivets 143, and extending through the central portion of the diaphragm and member 142 are outlet openings 145 which preferably are disposed in a circumferential series about the center of the diaphragm 130.

The exhaust openings 145 are normally closed by an exhaust valve 146 which takes the form of a check valve which opens whenever the pressure in the exhaust chamber is greater than the pressure on the exterior of the diaphragm 130. To this end, the valve 146 is formed of suitable resilient material such as rubber, and has a circular portion 147 which normally overlies all of the openings but which is yieldable and is displaced away from the openings 145 whenever the pressure within the exhaust chamber 140 exceeds the pressure on the exterior face of the diaphragm. The valve 146 also has a stern portion 148 which extends through an opening in the diaphragm 130 and a head portion 149 which serves to retain the stem portion 148 in the diaphragm 130.

A push rod 150 of generally U shaped form is secured to the inner face of the diaphragm 130 by the head 149. The push rod 150 is so dimensioned and positioned that when the diaphragm 130 is moved inwardly a sufiicient amount the push rod 150 bears against the central portion of the breather diaphragm 105 and moves it inwardly for a purpose hereinafter described.

Extending from the inlet chamber 110 is an outlet connection and extending from the exhaust chamber 140 is a similar inlet connection 161. The air hose 13 includes an intake or inhale portion 162 connected as by a clamp 163 to the outlet connection 160 and an exhaust or exhale portion 164 connected as by a clamp 165 to the connector 161. The two hose portions 162 and 164 are formed of corrugated rubber hose of conventional form.

The connecting portions 160 and 161 may be formed as separate members and welded into suitable openings in the intake housing and exhaust ring respectively, or they may be formed integrally therewith.

As clearly appears in FIGURE 4, there is connected between the ends of the hose portions 162 and 164 the mouthpiece 14 now to be described. The mouthpiece 14 includes a tubular portion 173 connected at its ends respectively to the corresponding ends of the hose portions 162 and 164 in a suitable manner, as by hose clamps 175 and 176 respectively, and having a bore 174 providing communication between the interiors of the portions 162 and 164. Extending from the main body portion 173 of the mouthpiece 14 is a lateral portion 177 having a bore 178 extending therethrough and leading from the bore 174 to the exterior. The mouthpiece has the usual shield or apron 179 and tooth grip lugs 190.

The lateral portion 177 extends from the main body 173 in offset relation thereto and above the medial plane passing through the axis thereof. Thus when the mouthpiece is in the normal position in the mouth of the user, the center of the bore 174 is disposed below the center line of the bore or passage 178. Consequently, any saliva which enters the passage 178 from the mouth of the user, will pass downwardly into the lower portion of the bore 174 and Will be trapped therein and will not tend to return to the mouth of the user. The trapped saliva will be expelled from the mouthpiece during the exhalation cycle.

The mouthpiece 14 is counterbored at each end and disposed in the counterbores of the body 173 are removable check valves 180 and 181 which abut the internal shoulders 260 and 261 defined by the counterbores. The valves 180 and 181 are identical in construction and are so arranged as to permit only a one-way flow of air through the hose. Thus the valve 180 permits flow of air from the hose portion 162 into the bore 174 but not in reverse direction and the valve 181 permits the flow of air from the bore 174 into the hose portion 164 but not in a reverse direction. Each valve includes a rigid cylindrical body portion 182 which is inserted in the end 7 of the mouthpiece body 173 and secured therein by the resiliency of the material of the body 173 and the clamping action of the corresponding hose clamp 175 or 176.

The shoulders 260 and 261 locate the valves 180 and 181 in the bore of the mouthpiece 14 for retention thereof in the mouthpiece, and the rigid body portions 182 of the valves serve as bases or backing on which the clamp rings 175 and 176 secure the mouthpiece. The mouthpiece body portion 173 is also provided with a pair of external annular stop shoulders 262 and 263. Each facing toward a respective end of the body portion 173 for abutment with the ends of the hoses 162 and 164. The external shoulders 262 and 263 are spaced a substantial distance inwardly of the outer ends of the rigid body portions of the valves 180 and 181 so that the body portion will be rigidized by the rigid body portions 182 of the valves when the ends 162 and 164 of the hoses are telescoped on the mouthpiece, as shown in FIGURE 4, until the end surfaces of the hoses abut the shoulders 262 and 263. Thus the rigid body portions of the valves 180 and 181 are located concentrically by abutment with the shoulders 260 and 261, and with the hose ends 162 and 164 by abutment of the end surfaces of the hose ends with the shoulders 262 and 263. The clamp rings 175 and 176 will secure the hose ends to the mouthpiece 14 and retain the valves 180 and 181 in the mouthpiece. The clamp rings 175 and 176 will tend to flow the material of construction of the hose ends 162 and 164 and trap this material between itself and the corresponding shoulders 262 and 263 to form beads 264 and 265. Beads 264 and 265 will increase the resistance of the clamped hoses to externally applied forces tending to draw the hose ends 162 and 164 from abutment with the shoulders 262 and 263.

Thus the shoulders 260-263 cooperate to locate the valves 180 and 181 and hose ends 162 and 164 concentrically so that a single clamp 175 or 176 can be employed to secure the hoses 162 and 164 to the mouthpiece and also retain the removable valves 180 and 181 in the mouthpiece.

The body portion 182 of the valve member carries a partition 183 formed with a plurality of ports 184 preferably of segmental shape. The ports are normally closed, but each valve member has a head 185 which normally overlies the ports 184 but which is sufficiently flexible and yielding to be displaced away from the ports 184 upon air pressure being applied thereto through the ports. The valve is secured in the partition by a stem 186 and a head 187.

The bodies of the values 180 and 181 preferably are formed of a rigid material such as a suitable rigid plastic, and the valve members 185 preferably are formed of a flexible resilient material such as rubber or synthetic rubber.

In the use of the device in accordance with my invention the pressure regulator, with the air hose and mouthpiece attached, is connected to a tank by the clamp 12, the clamping screw (not shown) being tightened so as to firmly clamp the outer end of the valve housing 22 against the neck 15 of the flask in sealing engagement therewith and to thereby place the bore 30 in communication with the outlet passage 16 of the flask.

The shut-off valve (not shown) is opened to admit air into the regulator from the flask. Inasmuch as initially the pressure in the chamber 21 is at that of the medium surrounding the device, the spring 65 causes the pressure member 55 to urge the push rod 61 downwardly to bear against the anvil 42 and maintain the valve 36 in open position. Thus the air from the flask may pass through the passage 16, the bore 30, the passages 38, the port 31, the bore 32 and the passages 63 into the chamber 21. Assuming the device to be in air, the pressure in the intake chamber 110 and the exhaust chamber 140 is equal and the diaphragm 105 is not displaced from its normal position. Accordingly, the demand valve is in closed position and air cannot escape therethrough.

Thus the pressure in the chamber 21 builds up to the desired amount, namely around 50 to pounds per square inch. When this occurs the diaphragm 50 is forced outwardly against the force of the spring 65 a suflicient amount to permit the valve 36 to close and cut off any further flow of air from the flask 10.

The user inserts the grip lugs 190 in his mouth and between his teeth with the shield 179 between his lips and his teeth so that there is no leakage of air past themouthpiece. The exhaust diaphragm 130 is subjected to the pressure of the surrounding medium, whether it be air or water. Assuming now that the user has entered the water and the body of the user and the pressure regulator are submerged in the water at a predetermined depth, the water exerts a pressure on the exhaust diaphragm 130 determined by the depth at which the pressure regulator -and more particularly the diaphragm 130is located.

Assuming that the user is neither exhaling nor inhaling, the apparatus is in what I term the static condition wherein the demand valve 80, the check valves 180 and 181, and the exhaust valve 146 are closed and the diaphragrns and 130 are in their normal neutral positions. The pressures throughout the device then are equalized. The water pressure exerted on the outer face of the diaphragm 130 tend to displace the diaphragm 130 inwardly a very slight amount and, owing to the resiliency of the diaphragm, it is stressed in a direction setting up a counter or restoring force on the diaphragm, tending to restore it to its original position. On the inner face of the diaphragm there is an air pressure force equal to the water pressure force on the outer face of the diaphragm less the counterforce tending to retore the diaphragm to its initial position. In other words, the force exerted by the air pressure on the inner face of the diaphragm 130 is less than the force exerted by the water pressure by the amount corresponding to the energy stored in the diaphragm by reason of its displacement and tending to restore it to its normal position and condition.

Since the pressure in the exhaust chamber is slightly less than that of the surrounding medium, and since the user is neither inhaling nor exhaling, the exhale valve 181 may open slightly and similarly the inhale valve 180 may open slightly to equalize the pressure within the intake chamber and the exhaust chamber 140. When the pressure is thus equalized the breather diaphragm 105 is in its neutral position and the demand valve 80 remains closed. Thus the pressure throughout the system is equalized at a value equal to the pressure in the exhaust chamber, which is slightly less than that of the surroundmg water.

When the user inhales, the inhale valve 180 (as shown in FIG. 3) is opened to allow air to pass therethrough to the mouthpiece and into the lungs of the user. This action reduces the pressure within the intake chamber 110, whereupon the breather diaphragm 105 is drawn inwardly and bears against the button 103 to rock the lever 100 which in turn rocks the lever 81 and fully opens the demand valve 80. The inward movement of the diaphragm 105 causes a reduction in pressure in the exhaust cham ber, and the exhaust diaphragm moves inwardly accordingly. The reduction of pressure in the intake chamber and consequent inward movement of the diaphragm resulting from the inhalation causes the valve to be opened so that the air can flow through to the lungs of the user. The valve 181 remains closed. Air flows from the pressure regulator chamber 21 into the intake chamber 110 in a quantity suflicient to meet the demand of the inhalation by the user.

Upon the cessation of the inhalation by the user the check valve 180 closes and pressure is built up in the chamber 110 until the diaphragm 105 is returned to its initial position (as shown in FIG. 2) and allows the demand valve 80 to close, whereupon no more air flows from the primary chamber 21 into the intake chamber 110. The diaphragm 105 also returns to its original position.

When the user exhales the exhale valve 181 is opened (as shown in FIG. 4) and air passes therethrough and through the hose portion 164 into the exhaust chamber 140. The increase in pressure in the exhaust chamber 140 moves the diaphragm 130 outwardly and finally causes the exhaust valve 146 to open and allow air to be discharged to the exterior of the regulator and into the surrounding water through the opening 145. Saliva trapped in the lower portion of the bore 174 will be expelled through the valve 181 by the exhalation of the user. The inhale valve is maintained closed during the exhale portion of the cycle.

During the exhale portion of the cycle the exhaust diaphragm 130 is moved outwardly as above described, and the exhaust valve 146 is opened. At the same time, owing to the pressure established in the exhaust chamber 140, the breather diaphragm 105 is moved inwardly a slight amount to open the demand valve slightly and equalize all pressure in the inhale hose portion 162 with that in the remainder of the device. This equalizing of pressure assists in exhaling because the user does not have to exhale against the entire pressure of the exhaust valve, but his exhalation is assisted by the pressure of the air passing through the hose from the intake chamber.

During normal use of the device the push rod 150, carried by the exhaust diaphragm 130, remains spaced from and out of engagement with the breather diaphragm 105. However, should the device be submerged substantially-that is to say, for example, a distance of several feet under the surface of the water without any inhalation by the userthe pressure of the water will cause the exhaust diaphragm 130 to be moved inwardly to an extent to which the push rod 150 effects inward movement of the end of the lever 100 and thereby opens the demand valve 80 to allow air to pass into the intake chamber and through the inhale valve 180 and into the lungs of the user. Thus even should the user forget to inhale, air will be supplied to his lungs and will cause involuntary action which will result in the user exhaling and initiating the breathing cycle.

It will be noted that the breather diaphragm 105 is not exposed to contact with the surrounding water but is exposed to air on both sides. The outer face of the breather diaphragm 165 is subjected to the pressure of the air in the exhaust chamber which is at the exhaust pressure or a lesser pressure, depending upon the portions of cycle at any moment. The inner face of the breather diaphragm 105 is subjected to a maximum pressure equal to the pressure of the air passing from the orifice 75 of the demand valve.

The breather diaphragm, which is the diaphragm against which the user must exert the pressure of his lungs in order to actuate the diaphragm is exposed only to air on each face thereof. It is not exposed to water pressure. Accordingly the breather diaphragm may move relatively freely during both the exhale and inhale cycle as the only inertia is that of the diaphragm itself and of the air. On the other hand, in a conventional underwater breathing device the water pressure is always applied against the outer face of the breather diaphragm and consequently upon inward movement of the diaphragm the water inertia tends to continue the inward movement of the diaphragm. On the other hand, upon the initiation of the outward movement of the diaphragm the initial inertia of the water must be overcome. In the present device there is no water inertia to be overcome or to effect continued inward movement of the diaphragm.

The elimination of the aforesaid water inertia on the breather diaphragm results in a more uniform breathing action and less resistance to the normal breathing action. Thus the device of the present invention is more comfortable and satisfactory to use inasmuch as the user does not have to exert any abnormal inhale and exhale force to operate the device as in the case of prior devices.

It will be noted that the breather diaphragm in the device of the present invention is not subjected to the pressure of the water. Accordingly there is no tendency for the diaphragm to be tilted or cocked when the device is in such position that one outer or peripheral portion of the diaphragm is at a lower depth than another peripheral portion. Accordingly, the demand valve is opened only when such action is dictated by the desired pressure in the intake chamber resulting from the inhale cycle and there is no possibility of the demand valve being opened or held against opening owing to any differential in water pressure over the different portions of the face of the breather diaphragm.

The exhaust diaphragm also is provided with a rigid central portion and this diaphragm moreover does not normally act to operate the demand valve. However, should the device be in such position that there is a greater pressure on one peripheral portion thereof than on another owing to the position of the diaphragm and to the fact that the water pressure on one peripheral portion is greater than on another, nevertheless because of the fact that the push rod is located centrally of the exhaust diaphragm and acts on the exact central portion of the breather diaphragm there will be no actuation of the demand valve because of any such diiferential pressure exerted by the water on the exhaust diaphragm 130.

It will be seen that inasmuch as the breather diaphragm 105 is not subjected to the pressure of the water surrounding the regulator, there is no danger of any spontaneous loss of air by reason of the fact that a greater pressure is exerted on the breather diaphragm than is exerted on the exhaust valve. Accordingly, it is immaterial whether the exhaust valve be placed above or below or any particular distance above the breather diaphragm. While I have shown a device wherein the exhaust valve is placed relatively close to the breather diaphragm, this is not at all necessary and the exhaust valve may be placed at any location above or below the breather diaphragm. Accordingly, it is immaterial what position the device takes relatively to the water in which it is located. Thus the user may swim in the normal face-down position, or on his back, or in any other position without causing spontaneous loss of air through the exhaust valve.

The device of the present invention requires a minimum of effort to operate it to supply air to the lungs of the user. As explained elsewhere herein, the breather diaphragm is not subjected to the pressure of the water but a somewhat lower pressure. Moreover, the water is not in contact with the diaphragm, and the latter is not subjected to the inertia of the water. Moreover, during the exhale portion of the breathing cycle, the demand valve is opened to supply air which aids in opening the exhaust valve and equalizes all pressures from the inlet chamber to the exhaust valve.

Inasmuch as the breather diaphragm of the present invention is not subject to cocking or water inertia and since it is effective only at the center thereof to open the demand valve, the diaphragm may be made comparatively larger than diaphragms employed in prior art devices and therefore is much more sensitive than smaller diaphragms.

The provision of two diaphragms provides a double protection for the device. For example, should the breather diaphragm be ruptured or leak, the outer, exhaust diaphragm would then function both as a breather diaphragm and as an exhaust valve diaphragm and the device would operate even though the breather diaphragm Were not effective. Thus, even though the inner dia phragm were ruptured or otherwise became ineffective, the user would still be able to operate the demand valve by the normal breathing operation and would be supplied with the air to permit his return to the surface. Also,

if the outer, exhaust diaphragm should be ruptured or otherwise caused to leak, the device would still operate. Under such circumstances, the breather diaphragm 105 would continue to operate but would be subjected to the pressure of the water thereon. In this event the exhale value 181 would function as the exhaust valve, and the breather diaphragm 105 would be subjected to the pressure of the water on the outer face thereof as in the case of conventional prior art underwater breathing devices.

It will be seen from the foregoing that the device of my invention is relatively simple, and no parts thereof require any critical adjustments. The simplicity thereof will assure long life without costly repairs and it can be manufactured and assembled readily. Moreover, it is extremely safe and positive in action, and provides not only all of the features and advantages of prior devices but embodies a number of features not present or possible in devices constructed in accordance with prior art teachings. It provides extremely easy breathing and furnishes air instantly to the user in any quantity desired.

The mouthpiece is of such construction that the valve chamber serves as a saliva trap from which the saliva is expelled by the exhaled air during the exhalation portion of the breathing cycle. Moreover, the valve chamber is depressed, and thus does not interfere with the face mask customarily worn by the user of the breathing device.

While I have referred to the device herein as being employed to supply air to the user, it will be understood that the device is not restricted to such use but may be employed to supply any breathable gas to the user. For example, under certain circumstances it may be desirable to provide in the tank or flask a breathable gas consisting of air enriched with oxygen, or pure oxygen. It will be understood that the mechanism of the device does not depend upon the nature of the gas supplied by the flask, but it is suitable for operation with any breathable gas.

I claim:

1. In underwater breathing apparatus including an intake hose and output hose, a mouthpiece comprising a unitary molded member having a generally tubular body portion defining an axial bore therethrough, a take-off portion integral with said body portion and extending laterally therefrom, said take-off portion having therethrough a passageway communicating with the interior of said body portion, said passageway extending substantially tangential to the top of said bore with the bottom of said passageway being disposed no lower than the axis of said bore, said take-off portion having an integrally molded shield at the outer end thereof and a pair of tooth grip lugs extending therefrom at the opposite sides of said passageway, said body portion having a pair of annular internal stop shoulders each spaced from and facing toward a respective end of said bore, a pair of identical check valves each including a rigid tubular portion, said valves being respectively mounted in the ends of said bore in abutment with said shoulders, the internal diameter of said bore adjacent to said rigid tubular portions of each of said valves being substantially equal to the internal diameter of said rigid tubular portion, each valve having a ported partition therein and a flexible valve head member mounted by said partition and yieldingly overlying said ports, the valve head member of one of said check valves being mounted on the outer side of the respective valve head member and the other of said check valves being mounted on the inner side of the respective valve head member whereby one of said check valves opens into said body portion and the other of said check valves opens out of said body portion, said body portion having a pair of external annular shoulders each facing toward a respective end of said body portion for abutment with the ends of said air hoses, said external shoulders being spaced a substantial distance inwardly of the outer ends of said rigid tubular portions of said check valves thereby to provide on said body portion substantially rigid tubular end sections for telescopingly receiving said hoses, said intake hose being connected to said inwardly opening valve and said output hose being connected to said outwardly opening valve, and means for securing said hoses to said mouthpiece.

2. A mouthpiece comprising a unitary molded member having a generally tubular body portion defining an axial bore therethrough,

a take-oif portion integral with said body portion and extending laterally therefrom,

said take-off portion having therethrough a passageway communicating with the interior of said body portion,

said passageway extending substantially tangential to the top of said bore with the bottom of said passageway being disposed no lower than the axis of said bore,

said take-off portion having an intergrally molded shield at the outer end thereof and a pair of tooth grip lugs extending therefrom at the opposite sides of said passageway,

said body portion having a pair of annular internal stop shoulders each spaced from and facing toward a respective end of said bore,

a pair of identical check valves, each including a rigid tubular portion mounted in the ends of said bore in abutment with said shoulders, a partition in said tubular portion having a port therein and a valve head covering said port,

the internal diameter of said bore adjacent to said rigid tubular portion of each of said valves being substantially equal to the internal diameter of said rigid tubular portion, one of said valve heads being mounted on the outer side and the other of said valve heads being mounted on the inner side of respective ones of said partitions whereby one of said valves opens into said body portion and the other of said valves opens out of said body portion,

said body portion of the mouthpiece having a pair of external annular stop shoulders each facing toward a respective end of said body portion for abutment with the ends of air hoses,

said external shoulders being spaced a substantial distance inwardly of the outer ends of said rigid tubular portions of said check valves thereby to provide on said body portion substantially rigid tubular end sections for telescopingly receiving air hoses.

References Cited by the Examiner UNITED STATES PATENTS 1,328,057 1/20 Ryan 128147 2,818,066 12/57 Glidden 128-l42 2,865,369 12/58 Kline l28-l42 2,823,670 2/62 Page 128142 RICHARD A, GAUDET, Primary Examiner. 

1. IN UNDERWATER BREATHING APPARATUS INCLUDING AN INTAKE HOSE AND OUTPUT HOSE, A MOUTHPIECE COMPRISING A UNITARY MOLDED MEMBER HAVING A GENERALLY TUBULAR BODY PORTION DEFINING AN AXIAL BORE THERETHROUGH, A TAKE-OFF PORTION INTEGRAL WITH SAID BODY PORTION AND EXTENDING LATERALLY THEREFROM, SAID TAKE-OFF PORTION HAVING THERETHROUGH A PASSAGEWAY COMMUNICATING WITH THE INTERIOR OF SAID BODY PORTION, SAID PASSAGEWAY EXTENDING SUBSTANTIALLY TANGENTIAL TO THE TOP OF SAID BORE WITH THE BOTTOM OF SAID PASSAGEWAY BEING DISPOSED NO LOWER THAN THE AXIS OF SAID BORE, SAID TAKE-OFF PORTION HAVING AN INTEGRALLY MOLDED SHIELD AT THE OUTER END THEREOF AND A PAIR OF TOOTH GRIP LUGS EXTENDING THEREFROM AT THE OPPOSITE SIDES OF SAID PASSAGEWAY, SAID BODY PORTION HAVING A PAIR OF ANNULAR INTERNAL STOP SHOULDERS EACH SPACED FROM AND FACING TOWARD A RESPECTIVE END OF SAID BORE, A PAIR OF IDENTICAL CHECK VALVES EACH INCLUDING A RIGID TUBULAR PORTION, SAID VALVES BEING RESPECTIVE MOUNTED IN THE ENDS OF SAID BORE IN ABUTMENT WITH SAID SHOULDERS, THE INTERNAL DIAMETER OF SAID BORE ADJACENT TO SAID RIGID TUBULAR PORTIONS OF EACH OF SAID VALVES BEING SUBSTANTIALLY EQUAL TO THE INTERNAL DIAMETER OF SAID RIGID TUBULAR PORTION, EACH VALVE HAVING A PORTED PARTITION THEREIN AND A FLEXIBLE VALVE HEAD MEMBER MOUNTED BY SAID PARTITION AND YIELDING OVERLYING SAID PORTS, THE VALVE HEAD MEMBER OF ONE OF SAID CHECK VALVES BEING MOUNTED ON THE OUTER SIDE OF THE RESPECTIVE VALVE HEAD MEMBER AND THE OTHER OF SAID CHECK VALVES BEING MOUNTED ON THE INNER SIDE OF THE RESPECTIVE VALVE HEAD MEMBER WHEREBY ONE OF SAID CHECK VALVES OPENS INTO SAID BODY PORTION AND THE OTHER OF SAID CHECK VALVES OPENS OUT OF SAID BODY PROTION, SAID BODY PORTION HAVING A PAIR OF EXTERNAL ANNULAR SHOULDERS EACH FACING TOWARD A RESPECTIVE END OF SAID BODY PORTION FOR ABUTMENT WITH THE ENDS OF SAID AIR HOSES, SAID EXTERNAL SHOUDLERS BEING SPACED A SUBSTANTIAL DISTANCE INWARDLY OF THE OUTER ENDS OF SAID RIGID TUBULAR PORTIONS OF SAID CHECK VALVES THEREBY TO PROVIDE ON SAID BODY PORTION SUBSTANTIALLY RIGID TUBULAR END SECTIONS FOR TELESCOPINGLY RECEIVING SAID HOSES, SAID INTAKE HOSE BEING CONNECTED TO SAID INWARDLY OPENINGS VALVE AND SAID OUTPUT HOSE BEING CONNECTED TO SAID OUTWARDLY OPENING VALVE AND MEANS FOR SECURING SAID HOSES TO SAID MOUTHPIECE. 